There was only one thing — the caption mistakenly referred Eugenie’s older sister, Princess Beatrice.
“This exclusive mug issued in commemoration of the wedding of HRH Princess Beatrice of York and Mr Jack Brooksbank is now available for purchase by following the link in the description,” the caption said.
Princess Beatrice is the older sister of Princess Eugenie, and acted as Maid Of Honour at her big day.
The post was swiftly deleted from the Palace’s Instagram account.
Princess Eugenie has had it tough following her Royal Wedding on October 12.
The royal is reportedly "upset" that Prince Harry and Meghan Markle chose to break their pregnancy news to the Royal Family at her wedding.
Eugnie’s mother Sarah, the Duchess of York, was said to be furious that the Duke and Duchess of Sussex had broken an unwritten rule of sharing big news at a wedding, taking attention away from the bride.
Fergie shared several Tweets following the news, trying to divert attention back on to her daughter.
As the news of the new royal baby swept the world, Ferguson — on what was also her 59th birthday — gushed that she was “so proud of Eugenie and Jack” after the lavish ceremony that saw 850 A-listers flock to Windsor.